Employee Benefit Plans - Amounts in Accumulated Other Comprehensive Loss on Consolidated Balance Sheets that have not been Recognized as Components of Net Periodic Pension Benefit Cost (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Net actuarial (loss)	$ (546)	$ (20,191)
Prior service credit	5,578	7,133
Total accumulated other comprehensive income (loss)	5,032	(13,058)
Income tax benefit (expense)	(1,886)	5,128
Total accumulated other comprehensive income (loss), net of tax	$ 3,146	$ (7,930)